fl oz

Units & Measurements abbreviation · US Customary and Imperial Unit

fl oz stands for Fluid ounce, a US customary and imperial unit abbreviation.

Volume unit for liquids: the US fluid ounce is 1/128 of a US gallon, about 29.57 mL, while the imperial fluid ounce is 1/160 of an imperial gallon, about 28.41 mL. US drink cans, bottles, shampoo and medicine cups are labeled in fl oz.

Example: Each can contains 12 fl oz (355 mL) of sparkling water.

Usage notes

The fluid ounce measures volume, not weight; packaging labels oz for weight and fl oz for volume. For nutrition labeling, US rules round 1 fl oz to 30 mL. Because the imperial pint holds 20 smaller fluid ounces and the US pint 16 larger ones, the British pint is still about 20 percent bigger. TSA's carry-on liquid limit of 3.4 fl oz corresponds to 100 mL.

Related abbreviations

More US customary and imperial unit abbreviations

• cu ft – Cubic foot
• cu in – Cubic inch
• cu yd – Cubic yard
• cwt – Hundredweight
• dr – Dram
• dwt – Pennyweight
• ft – Foot
• ftm – Fathom
• fur – Furlong
• gal – Gallon
• gi – Gill
• gr – Grain

See all 43 US customary and imperial unit abbreviations →

Edited by the AbbreviationList.com team. Spotted an error or a missing meaning? Contact us.